Читать книгу Encyclopedia of Renewable Energy - James Speight G., James G. Speight - Страница 266

Bunker fuel is technically any type of fuel oil used aboard ships. It gets its name from the containers on ships and in ports that it is stored in; in the days of steam, they were coal bunkers, but now, they are bunker-fuel tanks.

Bunker fuel is the colloquial term for fuel oil used by marine vessels. Bunker fuels A, B, and C are respectively downgrading quality-classifications of fuel oil, characterized by their boiling points, carbon-chain lengths, and viscosities, all of which contribute to their value (in other words, Bunker A is more valuable than Bunker C). Currently, most of the global shipping fleet relies on diesel Bunker C fuel oil which contributes significant amounts of greenhouse gas emissions, sulfur, and other emissions that contribute negatively to climate change and negative environmental and human health impacts.

More specifically, bunker A is No. 2 fuel oil, bunker B is No. 4 or No. 5, and bunker C is No. 6. Since No. 6 is the most common, bunker fuel is often used as a synonym for No. 6. No. 5 fuel oil is also called navy special fuel oil or just navy special, No. 6 or 5 are also called furnace fuel oil (FFO); the high viscosity requires heating, usually by a recirculated low pressure steam system, before the oil can be pumped from a bunker tank. In the context of shipping, the labeling of bunkers as previously described is rarely used in modern practice.